Technical Abstract:
Atrazine (ATR) has been widely applied in the US Midwestern states. Public health and ecological concerns have been raised about contamination of surface and ground water by ATR and its chlorinated metabolites, due to their toxicity and potential carcinogenic or endocrinology effects. Phytoremediation has been proven to be one of the most cost-effective mitigation practices to remove atrazine from surface runoff derived from agronomic operations. Ongoing research has identified several plant species showing promising capacity to degrade most of the soil atrazine to less toxic or less mobile metabolites in the rhizosphere. However, the mineralization of atrazine and its chlorinated metabolites in the rhizosphere has been shown to be limited to less than 2-10% of the applied ATR under both laboratory and field conditions. Despite the persistence of atrazine and its metabolites in the environment, a few bacterial strains capable of completely mineralizing ATR, including Pseudomonas sp. ADP, have been isolated in the past decade from atrazine spill sites. These bacteria contained a series of genes encoded on a self-transmissible plasmid (pADP-1) responsible for various processes of atrazine degradation resulting in complete ring cleavage and rapid mineralization of atrazine to carbon dioxide. We proposed to investigate the effect of Pseudomonas sp. ADP on the degradation of atrazine following its introduction into the soil rhizosphere. The developed knowledge will be transferred for future field application to reduce the transport of atrazine and its metabolites to water resources.